Universal parallel drafting device



Marel; s, 192s. l 1,661,538

M. MARZET-rl UNIVERSAL PARALLEL DRAFTING DEVIE Filed ve. i1v. 1924 NQIO l (1 Patented Mar. 6, 1928.

i UNITED STATES MANLIO MARZETTI, OF MILAN, ITALY.

UNIVERSAL PARALLEL DRFTING DEVICE.

Application filed December 17, 1924, Serial No. 756,519, and in Italy December 20, 1923.

The invention relates to an improved drawing instrument for use in drawing parallel lines in any desired direction. The improved instrument is illustrated, by way of example, in the accompanying drawing. The instrument comprises two systems. of swivel parallelograms 1v and 2, each being constituted by three rods 3, 4,5 and 6, 7, 8,

respectively, the ends of which are pivotally 0 connected to *three equilateral triangles 9, 10

and 11.

The upper triangle 9 serves as a ybase for the movements of the parallelograms and comprises a U-shaped metal plate 12 which vis rigidly attached by means of screws to the rear of the upper edge of the drawing board 13.

The rods 3 and 4 have their ends pivot-` ally mounted at the corners 14 and 15, on theupper face of the triangle 9, while one of the ends of the rod 5 is pivoted at the third corner 160i the triangle 9, but on the lower. face of the triangle so that the said rod 5- lies in a diiierentv plane from that of the rods 3 and 4:. The opposite ends ofthe rods 3, 4 and 5 are all Vpivoted on theV upper face of the triangle 10, at the` corners 17, 18 and 19 respectively. The pivoting point 19 lies at a lower 'level than that of the pivoting points 17 and 18, in order to maintain therod 5 in a different plane from that of the rods 3 and 4. The upper endsof the rods S. 7 and 6 of the second system of parallelograms are pivotally mounted at theV corners 17, 18 and 19 respectively of the triangle 10, but on the lower face thereof; and the pivoting oint 17 lies at a lower level than that of t e pivoting points 18 and 19, in order to maintain the rod S in a different plane from that of the rods 6 and 7. The opposite ends of such rods 7, 6 and. 8 are pivotallyy mounted at the corners 20, 21 and 22 respectively of thel triangle 11; and the pivot-ing point 22 lies at a lower level than that of the pivoting points 20 and 21 in order to maintain the rod 8 in a differ` ent plane Jfrom that of the rods 6 and 7.

The triangle 11 is provided with a protractor 23 which'is pivotally mounted at 24, on an extension of the triangle 11; the protractor being capable of adjustment to any desired position and having extending therefrom two rulers 25 and'26 arranged at an angle of 901o to each other.

Through these systems of parallelograms, each of which is constituted by three rods, it is possible to rotate each system of parallelograms about 1800, while maintaining always the precision of the parallelism inthe movement of the rulers, since the dis tance between the outer rods of the parallelograms vmay never be less than the height of the base triangle 9 and the angle of the This arrangement gives much `greater pre- `cision than is obtainable by means ot the usual two-rods-parallelograms and also enables the ruler movements to cover the whole surface of the drawing board .even

when vrods having `a very limited length are employed.

lVhat I claim is An instrument forense in drawing parallel lines comprising a. Xed base triangle, a second triangle, three parallel rods pivotally connecting the corners Vof the base triangle with the corners of the second triangle, a

In testimony whereof he aflixes his signature.

. MANLIo MARZETTI. 1

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